The invention relates to an apparatus for making a predetermined quantity of a brewed beverage, in particular coffee, having a device for heating the water for brewing a batchwise-operating automatic brewing apparatus, which is followed by a collection vessel for the charge to be brewed, an inlet valve in front of the brewing apparatus and an outlet valve behind the brewing apparatus as well as a control device. Apparatuses of this type are used for making available relatively large quantities of freshly brewed coffee and, generally in addition, corresponding quantities of hot water for making tea.
An apparatus of the type described at the outset is known from German Offenlegungsschrift No. 2,526,570. This automatically operating machine is also referred to as an automatic machine for making large quantities of fresh coffee. This apparatus has a batchwise-operating, automatic brewing device, the brewing chamber being followed by three collection vessels each of which is provided with a lower and upper level probe. The charge to be brewed is determined by the capacity of each collection vessel or, respectively, by the arrangement of the level probes, so that each vessel is suitable for receiving a complete brewed charge. The freshly brewed coffee can be drawn off at an outlet via appropriate outlet valves. This known automatic machine for making large quantities of fresh coffee is very variable with regard to the volume of the quantities of coffee to be drawn off, i.e. it is possible to fill both individual cups and pots and carafes. However, this is possible only with monitoring by an operator. The three collection vessels are connected to the apparatus via an involved control device which follows a certain sequence during filling, i.e. during the passage of the individual charges to be brewed, and during removal of the coffee in a manner such that freshly brewed coffee is not mixed with coffee already present in the collection vessel. This advantage is cancelled out by the expenditure for the three collection vessels. As a result of this intermediate storage of the coffee, the latter when poured is not completely fresh, in particular when the quantities removed per unit time are only relatively small.
Furthermore, infusion apparatuses are known which operate without pressure and have a filter pan. Apparatuses of this type are not automatic machines but apparatuses in which appropriate procedures, thus for example inserting the filter paper and metering in the powder, have to be carried out for each brewing operation, i.e. for each charge. The filter pan has to be emptied and cleaned after each charge. Using such apparatuses it is of course also possible to make a carafe of coffee, in particular when the capacity of the carafe corresponds to the brewed charge. These known apparatuses are comparatively inexpensive to manufacture but expensive to operate, since they require the presence of an operator during the brewing operation. The performance of the apparatus is limited. Removal of a carafe, partially filled with coffee, from the apparatus does not interrupt the brewing operation so that the coffee continues to flow out.
German Pat. No. 1,454,224 discloses an automatically operating apparatus, that is an apparatus in which the individual brewing operations take place batchwise and automatically controlled by a control device. The brewing chamber is followed by a first collection vessel which is intended for receiving a charge of brewed coffee. The charge to be brewed is determined by two level probes arranged in the collection vessel. Downstream from the collection vessel is arranged a large-capacity storage container, as a warming container, which is likewise fitted with level probes which, when a corresponding quantity of brewed coffee is drawn off, can trigger a further brewing operation, so that a certain quantity of coffee can always be kept available. The disadvantage of this apparatus is that here too the brewing chamber is followed by various containers and the brewed coffee is transferred from one container into the other so that the coffee ultimately poured out is not entirely freshly brewed. Moreover, the disadvantage arises that freshly brewed coffee transferred from the collection vessel into the storage container is always mixed with stale coffee in the storage container. The latter has a tap at its outlet, which can be actuated in a corresponding manner. In this way it is also possible to use this apparatus for drawing off a carafe of coffee. However, in this case too it is necessary for the operator to be present.
German Offenlegungsschrift No. 2,048,163 discloses a dispensing apparatus for beverages, in particular coffee, in which a large-capacity storage container is followed by a measuring container which is fitted with level probes at varying heights, corresponding to the particular desired quantity to be drawn off for an individual cup or for a pot. For placing the individual cup or the pot underneath the outlet of an appropriate valve a supporting base is provided which is mounted on a spring so that, when an empty individual cup or a pot is placed on top of it, this supporting base is lowered to varying extents as a function of the different weight of the particular empty vessel. This at the same time provides for a switch which responds to the weight or, in another embodiment, to the shape of the particular container to be filled, so that the particular level probe selected in the measuring container transfers a corresponding quantity of coffee from the storage container first into the measuring container and then from the latter into the individual cup or the pot. This sensor hence serves for determining whether an individual cup or a pot has been placed underneath the outlet and accordingly and in conjunction with the measuring container determines the quantity flowing out. The sensor is thus an identification sensor. However, a further sensor is also provided which actuates a position switch connected into the circuit of the solenoid valve which controls the flow from the storage container into the measuring container and from the latter into the individual cup or the pot. This switch is a sort of position switch since it only permits transfer of coffee from the storage container into the measuring container when an individual cup or a pot is in position on the supporting base. However, the individual brewing operations, as are necessary in making coffee, are unaffected by either the identification sensor or the position switch.
The common feature of all the known prior art apparatuses of the types under discussion here is that the brewing apparatus or the actual brewing chamber is followed by at least one, frequently however more than one, collection vessel(s) also of different size within the apparatus. This reveals a certain unyielding way of thinking in which it is considered necessary for the brewing chamber to be followed, first of all, by a firmly installed collection vessel, so that the brewed charge of coffee can also be received. The use of such fixed collection vessels is of course particularly obvious when the apparatuses have a relatively large output and/or when they operate automatically.